PHP mail forum, submit?

hey guys. i know someone can help me out on this
i have this code

$Subject = "Test";                         
$toEmail = "[email protected]";       

mail($fromEmail, $Subject, $nMessage."
From: ".$fromName."<".$fromEmail.">");

<title>Request form</title>
<body bgcolor="#FFFFFF">
<form method="post" action="<? echo($PHP_SELF) ?>">
Your E-mail: 

<input type="text" name="fromEmail" size="25"> 

Your Name: <input type="text" name="fromName" size="25"> 

Your Message: 

<textarea cols="50" rows="5" name="nMessage">Your Message Here...

how do i creat a submit button?? i tried adding a form button with the name submit and relative data but it doesnt even show up??